Infection-induced expansion of a MHC Class Ib-dependent intestinal intraepithelial gammadelta T cell subset

Salmonella species invade the host via the intestinal epithelium. Hence, intestinal intraepithelial lymphocytes (iIELs) are potentially the first element of the immune system to encounter Salmonella during infection. In this study, we demonstrate, in a mouse model, the expansion of a CD8alphabeta(+)CD94(-)TCRgammadelta(+) T cell subset within the iIEL population in response to oral infection with virulent or avirulent Salmonella. This population can be detected 3 days following infection, represents up to 15% of the TCRgammadelta(+) iIELs, and is dependent on the MHC class Ib molecule T23 (Qa-1). Qa-1 is expressed by intestinal epithelial cells and thus accessible for iIEL recognition. Such cells may play a role in the early immune response to Salmonella.     

The inhibition of apoptosis in myositis and in normal muscle cells

The mechanism of injury and death of muscle cells in the inflammatory myopathies (dermatomyositis, polymyositis, and inclusion body myositis) remains obscure. We and others have not detected apoptosis in the muscle biopsies from patients with myositis despite clear evidence of cell damage and loss. We provide evidence in this study that Fas ligand (FasL) as well as Fas is present on muscle cells and inflammatory cells in myositis biopsies: Fas is present on most muscle cells and lymphocytes, and FasL is present on degenerating muscle cells and many infiltrating mononuclear cells. The expression of both Fas and FasL in the inflamed tissue makes the absence of apoptosis more striking. To address the mechanisms of this resistance to classical apoptosis in muscle cells, we have investigated the expression of the antiapoptotic molecule FLICE (Fas-associated death domain-like IL-1-converting enzyme)-inhibitory protein (FLIP) in muscle biopsies of myositis patients and in cultured human skeletal muscle cells. Using laser capture microscopy, we have shown that FLIP is expressed in the muscle fibers and on infiltrating lymphocytes of myositis biopsies. Furthermore, we have shown that FLIP, but not Bcl-2, is expressed in cultured human skeletal muscle cells stimulated with proinflammatory cytokines, and inhibition of FLIP with antisense oligonucleotides promotes significant cleavage of poly(ADP-ribose) polymerase autoantigen, a sensitive indicator of apoptosis. These studies strongly suggest that the resistance of muscle to Fas-mediated apoptosis is due to the expression of FLIP in muscle cells in the inflammatory environment in myositis.     

Ecological niche modeling for conservation planning of an endemic snail in the verge of becoming a pest in cardamom plantations in the Western Ghats biodiversity hotspot

Conservation managers and policy makers are often confronted with a challenging dilemma of devising suitable strategies to maintain agricultural productivity while conserving endemic species that at the early stages of becoming pests of agricultural crops. Identification of environmental factors conducive to species range expansion for forecasting species distribution patterns will play a central role in devising management strategies to minimize the conflict between the agricultural productivity and biodiversity conservation. Here, we present results of a study that predicts the distribution of Indrella ampulla, a snail endemic to the Western Ghats biodiversity hotspot, which is becoming a pest in cardamom (Ellettaria cardamomum) plantations. We determined the distribution patterns and niche overlap between I. ampulla and Ellettaria cardamomum using maximum entropy (MaxEnt) niche modeling techniques under current and future (2020–2080) climatic scenarios. The results showed that climatic (precipitation of coldest quarter and isothermality) and soil (cation exchange capacity of soil [CEC]) parameters are major factors that determine the distribution of I. ampulla in Western Ghats. The model predicted cardamom cultivation areas in southern Western Ghats are highly sensitive to invasion of I. ampulla under both present and future climatic conditions. While the land area in the central Western Ghats is predicted to become unsuitable for I. ampulla and Ellettaria cardamomum in future, we found 71% of the Western Ghats land area is suitable for Ellettaria cardamomum cultivation and 45% suitable for I. ampulla, with an overlap of 35% between two species. The resulting distribution maps are invaluable for policy makers and conservation managers to design and implement management strategies minimizing the conflicts to sustain agricultural productivity while maintaining biodiversity in the region.     

'Partitagin' a hemorrhagic metalloprotease from Hippasa partita spider venom: role in tissue necrosis

The poisonous bite by Hippasa partita, a funnel web spider from the Indian subcontinent has been demonstrated to give rise to severe dermo- and myonecrosis. In this work a hemorrhagic metalloprotease, Partitagin was purified from H. partita venom by successive chromatography on Sephadex G-100, DEAE Sephadex A-50 and Biosep DEAE columns. SDS-PAGE, reversed phase HPLC on a C(4) column, N-terminal amino acid sequencing and MALDI-TOF mass spectrometry confirmed the homogeneity. Partitagin was assayed using fat free casein as substrate. EDTA, 1,10-phenanthroline and cyanide, inactivated it irreversibly while, EGTA, PMSF, leupeptin, pepstatin and aprotinin did not inhibit. The presence of Zn(+2) was confirmed by atomic absorption spectrometry. Partitagin caused hemorrhage when tested in a mouse model. Light microscopy of skin tissue sections at the site of injection revealed extensive damage of extracellular matrix (ECM) in which the basement membrane surrounding blood vessels and capillaries showing signs of extensive destruction and also loss of vessel wall integrity. Similar intense damage was also noticed in the ECM of muscle tissue sections but with no damage caused to myocytes. Partitagin showed specificity of action on the components of ECM and degraded collagen type-IV and fibronectin but not collagen type-I. Partitagin was devoid of edema, myotoxicity and lethality. This is the first report on the isolation and characterization of a toxin from spider venom in the Indian subcontinent.     

Genetic diversity and relationships in mulberry (genusMorus) as revealed by RAPD and ISSR marker assays

Background  

The genus Morus, known as mulberry, is a dioecious and cross-pollinating plant that is the sole food for the domesticated silkworm, Bombyx mori. Traditional methods using morphological traits for classification are largely unsuccessful in establishing the diversity and relationships among different mulberry species because of environmental influence on traits of interest. As a more robust alternative, PCR based marker assays including RAPD and ISSR were employed to study the genetic diversity and interrelationships among twelve domesticated and three wild mulberry species.     

Metallic Layered Polyester Fabric Enabled Nickel Selenide Nanostructures as Highly Conductive and Binderless Electrode with Superior Energy Storage Performance

Highly flexible and conductive fabric (CF)‐supported cauliflower‐like nickel selenide nanostructures (Ni₃Se₂ NSs) are facilely synthesized by a single‐step chronoamperometry voltage‐assisted electrochemical deposition (ECD) method and used as a positive electrode in supercapacitors (SCs). The CF substrate composed of multi‐layered metallic films on the surface of polyester fibers enables to provide high electrical conductivity as a working electrode in ECD process. Owing to good electrical conductivity, high porosity and intertwined fibrous framework of CF, cauliflower‐like Ni₃Se₂ NSs are densely integrated onto the entire surface of CF (Ni₃Se₂ NSs@CF) substrate with reliable adhesion by applying a chronoamperometry voltage of ?1.0 V for 240 s. The electrochemical performance of the synthesized cauliflower‐like Ni₃Se₂ NSs@CF electrode exhibits a maximum specific capacity (C _SC) of 119.6 mA h g^?1 at a discharge current density of 2 A g^?1 in aqueous 1 m KOH electrolyte solution. Remarkably, the specific capacity of the same electrode is greatly enhanced by introducing a small quantity of redox‐additive electrolyte into the aqueous KOH solution, indicating the C _SC≈251.82 mA h g^?1 at 2 A g^?1 with good capacity retention. Furthermore, the assembled textile‐based asymmetric SCs achieve remarkable electrochemical performance such as higher energy and power densities, which are able to light up different colored light‐emitting diodes.     

Microsatellites in the silkworm, Bombyx mori: abundance, polymorphism, and strain characterization.

We have isolated and characterized microsatellites (simple sequence repeat (SSR) loci) from the silkworm genome. The screening of a partial genomic library by the conventional hybridization method led to the isolation of 28 microsatellites harbouring clones. The abundance of (CA)n repeats in the silkworm genome was akin to those reported in the other organisms such as honey bee, pig, and human, but the (CT)n repeat motif is less common compared to bumble bee and honey bee genomes. Detailed analysis of 13 diverse silkworm strains with a representative of 15 microsatellite loci revealed a number of alleles ranging from 3 to 17 with heterozygosity values of 0.66-0.90. Along with strain-specific microsatellite markers, diapause and non-diapause strain-specific alleles were also identified. The repeat length did not show any relationship with the degree of polymorphism in the present study. The co-dominant inheritance of microsatellite markers was demonstrated in F1 offspring. A list of primer sequences that tag each locus is provided. The availability of microsatellite markers can be expected to enhance the power and resolution of genome analysis in silkworm.     

A mouse model of inherited choline kinase β-deficiency presents with specific cardiac abnormalities and a predisposition to arrhythmia

The CHKB gene encodes choline kinase β, which catalyzes the first step in the biosynthetic pathway for the major phospholipid phosphatidylcholine. Homozygous loss-of-function variants in human CHKB are associated with a congenital muscular dystrophy. Dilated cardiomyopathy is present in some CHKB patients and can cause heart failure and death. Mechanisms underlying a cardiac phenotype due to decreased CHKB levels are not well characterized. We determined that there is cardiac hypertrophy in Chkb^−/− mice along with a decrease in left ventricle size, internal diameter, and stroke volume compared with wildtype and Chkb^+/− mice. Unlike wildtype mice, 60% of the Chkb^+/− and all Chkb^−/− mice tested displayed arrhythmic events when challenged with isoproterenol. Lipidomic analysis revealed that the major change in lipid level in Chkb^+/− and Chkb^−/− hearts was an increase in the arrhythmogenic lipid acylcarnitine. An increase in acylcarnitine level is also associated with a defect in the ability of mitochondria to use fatty acids for energy and we observed that mitochondria from Chkb^−/− hearts had abnormal cristae and inefficient electron transport chain activity. Atrial natriuretic peptide (ANP) is a hormone produced by the heart that protects against the development of heart failure including ventricular conduction defects. We determined that there was a decrease in expression of ANP, its receptor NPRA, as well as ventricular conduction system markers in Chkb^+/− and Chkb^−/− mice.